OF ARTS AND SCIENCES. 63 



rows are a beautiful pale cobalt-blue. The two dorsal tubercles of the 

 2d and 3d thoracic segments are deep orange (afterwards becoming 

 coral-red)«; the homologous dorsal abdominal ones, including the sin- 

 gle median one on the 8th segment, are lemon-yellow. The body is 

 tinged with blue, especially on the thoracic segments. The spiracles 

 are white with a fine black circle, and contain a straight linear central 

 mark. All the bristles are still long, radiated, and are black. 



In this stage the four dorsal tubercles of the 2d and 3d thoracic 

 segments are larger than any others on the body ; and those on the 

 first seven abdominal segments are of nearly uniform size ; the single 

 one on the 8th segment being nearly twice as thick. 



In this stage the eight to ten black dorsal and lateral spots dwindle 

 in size, becoming less conspicuous ; but the black spots on the side of 

 the head and on the sides of the abdominal lees are large and distinct. 



Stage V. and lad. — Length 40-45 mm. One which moulted about 

 the 9th of July had a pea-green head and prothoracic segment; the 

 head marked with a roundish black spot on each side, below which is 

 a large black patch bearing the ocelli, and lower down a black spot. 

 The body is pea-green, washed with cobalt-blue along the back, be- 

 ginning with the 2d thoracic and ending with the 8th abdominal 

 segment, and the black spots along the back and sides have disappeared. 

 Of the lowest lateral row of five small tubercles, the three thoracic 

 and those on the first two abdominal segments are black ; those on the 

 third and fifth are blue at the end, but the bristles are black. All the 

 prothoracic, and the two rows of lateral (the subdorsal and infraspi- 

 racular) tubercles are cobalt-blue. The two dorsal tubercles of the 

 2d and 3d thoracic segments are deep coral-red ; the corresponding 

 ones on abdominal segments 1 to 7, and the single one on the 8th 

 segment, are lemon-yellow. 



The spiracles are now white with a narrow black ring, but no cen- 

 tral dark line. The thoracic feet are green, but black at the end. 

 The black spots on the sides of the pea-green abdominal feet are n vo 

 obsolete ; the plantae are bluish. 



July 25-26. Some individuals were observed while moulting into 

 the last stage, their length after exuviation being 47 mm.; they became 

 after feeding still larger. This stage differs from Stage [V. in the 

 tubercles on the first abdominal segments being much larger and more 

 spherical than before, and orange rather than yellow, and thus in size, 

 color, and the spines being more like the four coral-red thoi 

 tubercles than the other dorsal abdominal ones. 



On the 1st abdominal, as well as the thoracic round-headed tubercles, 



